1. Field of the Invention
The present invention relates to a vehicle seat assembly, and in particular, a seat assembly including an airbag.
2. Background Art
Vehicles today are increasingly equipped with side airbags, which may be in the form of a side air curtain disposed in a headliner of the vehicle, or alternatively, may be an airbag disposed within a vehicle seat assembly. One limitation of airbags that are located within a seat assembly, is that the airbag needs to break through the seating material before it can fully deploy to protect a vehicle occupant. During deployment, such an airbag may encounter foam, or other seat pad materials, and must then break through a seat trim cover in order to escape from the seat assembly.
A number of attempts have been made to facilitate deployment of airbags from and through a vehicle seat assembly. One such device is described in U.S. Pat. No. 5,816,610 issued to Higashiura et al. on Oct. 6, 1998. Higashiura et al. describes a seat structure having a side impact airbag apparatus. A seat back pad of the seat structure may be made from foam, in which case the airbag apparatus is surrounded by a lining member. The lining member has a perforation to facilitate its breaking when the airbag deploys. The seat back itself is covered with a surface layer having a seam almost directly opposite the perforation in the lining member. In this way, the airbag deploys through the perforation in the lining member, breaks through the foam of the seat pad, and exits the seat structure through the seam in the surface layer. One limitation of the seat structure described in Higashiura et al., is that the airbag must deploy through the seat pad prior to exiting the seat structure. In particular, the airbag, which may be moving with very high velocity, impacts the foam seat pad as it exits the seat structure. This can cause pieces of the seat pad to be expelled from the seat as the airbag exits the seat cover. Therefore, a need exists for a seat assembly that includes protection for the seat pad from the deploying airbag.